UNIVERSITY OF CALIFORNIA PUBLICATIONS 

COLLEGE OF AGRICULTURE 

AGRICULTURAL EXPERIMENT STATION 

BERKELEY, CALIFORNIA 



A SELF-MIXING DUSTING MACHINE 
FOR APPLYING DRY INSECTICIDES 

AND FUNGICIDES 



BY 
RALPH E. SMITH and JOSEPH P. MARTIN 



BULLETIN No. 357 

April, 1923 



UNIVERSITY OF CALIFORNIA PRESS 
BERKELEY 

1923 



David P. Barrows, President of the University. 

EXPERIMENT STATION STAFF 

HEADS OF DIVISIONS 

Thomas Forsyth Hunt, Dean. 

Edward J. Wickson, Horticulture (Emeritus). 

, Director of Resident Instruction. 

C. M. Haring, Veterinary Science, Director of Agricultural Experiment Station. 

B. H. CrocHeron, Director of Agricultural Extension. 

C. B. Hutchison, Plant Breeding, Director of the Branch of the College of 

Agriculture, Davis. 
H. J. Webber, Sub-tropical Horticulture, Director of Citrus Experiment Station. 
William A. Setchell, Botany. 
Myer E. Jaffa, Nutrition. 
Ralph E. Smith, Plant Pathology. 
John W. Gilmore, Agronomy. 
Charles F. Shaw, Soil Technology. 
John W. Gregg, Landscape Gardening and Floriculture. 
Frederic T. Bioletti, Viticulture and Fruit Products. 
Warren T. Clarke, Agricultural Extension. 
Ernest B. Babcock, Genetics. 
Gordon H. True, Animal Husbandry. 
James T. Barrett, Plant Pathology. 
Walter Mulford, Forestry. 
W. P. Kelley, Agricultural Chemistry. 
H. J. Quayle, Entomology. 
Elwood Mead, Rural Institutions. 
H. S. Reed, Plant Physiology. 
L. D. Batchelor, Orchard Management. 
W. L. Howard, Pomology. 
*Frank Adams, Irrigation Investigations. 

C. L. Roadhouse, Dairy Industry. 
R. L. Adams, Farm Management. 

W. B. Herms, Entomology and Parasitology. 
John E. Dougherty, Poultry Husbandry. 

D. R. Hoagland, Plant Nutrition. 
G. H. Hart, Veterinary Science. 

L. J. Fletcher, Agricultural Engineering. 
Edwin C. Voorhies, Assistant to the Dean. 

DIVISION OF PLANT PATHOLOGY 

R. E. Smith E. H. Smith 

W. T. Horne B. A. Rudolph 



* In cooperation with Division of Agricultural Engineering, Bureau of Public Roads, U. S. 
Department of Agriculture. 



A SELF-MIXING DUSTING MACHINE FOR APPLYING 
DRY INSECTICIDES AND FUNGICIDES 

BY 

RALPH E. SMITH and JOSEPH P. MARTIN 



The use of nicotine dust as an insecticide, which was described by 
the senior writer in Bulletin 336 of this station, has aroused much 
interest all over the United States. The advantages of the quick and 
easy application to be secured by this method are of value in the 
control of a number of insects which are in general not being handled 
satisfactorily by the liquid spray method. Among the California 
species of such insects may be mentioned the walnut aphis, pea aphis, 
melon aphis, prune thrips, and citrus thrips. The use of the nicotine 
dusting method has, however, at present, some drawbacks which, in 
the writer's opinion, must be largely remedied before it can become a 
complete success. The difficulties are connected with the manufacture, 
distribution, and use of nicotine dust on a commercial scale, as opposed 
to limited or experimental work. Several companies, in various parts 
of the country, are at present putting nicotine dusts upon the market, 
but, as a rule, with only partial success from the standpoint of either 
themselves or their customers. The usual method of manufacture 
consists in mixing the desired amount of nicotine (usually in the form 
of nicotine sulfate solution) with lime, clay, gypsum, or some other 
inert carrier ; then pulverizing and working the product in various 
ways to make it fine, dry, and uniform. Other materials, like sulfur 
and lead arsenate, are added if desired. The finished product is 
packed in air-tight steel drums or cans to prevent loss of nicotine by 
volatilization. 

There are three serious disadvantages in this method when it 
is used on a large scale. 1. The cost of the material to the consumer 
is excessive. This must be the case, when products that are composed 
almost entirely of inert, low grade " filler" are subjected to manufac- 
turing costs plus several profits, packed in expensive containers, and 
shipped and sold on the same basis as high grade insecticides. The 
average nicotine dust contains about 98 per cent of inert material, of 
no value except as a carrier of the nicotine. In a liquid spray this is 
replaced by the water, which costs nothing. Material like hydrated 



498 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 

lime, suitable for the carrier in the dust can be purchased almost any- 
where at a price of between one and two cents a pound. Since, how- 
ever, the consumer must at present buy his nicotine dust ready 
mixed at a factory, he pays many times this amount for the carrier. 
This difficulty is not as serious where the material is used on a rather 
small scale, but in the extensive, general use of nicotine dust the 
unavoidably high cost is a very serious drawback. 2. The amount of 
nicotine in most of the mixtures which have thus far appeared on the 
market has been extremely uncertain and variable, and often below 
the amount calculated, no matter how honest the intentions of the 
manufacturer. This fact is probably due to the volatile nature of 
nicotine, which causes constant losses during mixing and subsequent 
storage. 3. Nicotine in dust form has a very low efficiency in propor- 
tion to that of the same amount in liquid form. This is especially 
true at low temperatures, and is due to slow volatilization. For this 
reason, the more resistant insects require dust containing excessive 
amounts of nicotine, most of which is wasted. This waste causes 
prohibitive expense when the use of nicotine dust against such insects 
is attempted on a large scale. 

The manufacture of nicotine dust was originally carried on by the 
California Walnut Growers' Association for its own members, at cost. 
Various facilities which had to be maintained in any event for other 
purposes were utilized, thus keeping down the overhead expense. The 
material, after being mixed in a rather crude way, was packed in cheap 
containers and hauled out in trucks by the consumers themselves for 
immediate use in nearby orchards. This method was cheap and effec- 
tive. The commercial manufacture and distribution of nicotine dust 
for general use, on the other hand, has proved to be a far different 
matter. It should not, however, be inferred that this work has been 
a failure. On the contrary, there has been produced and sold much 
material which has given good results in the control of various insects. 
Methods of manufacture have lately been improved so that the nicotine 
dusts now on the market are, in general, better and cheaper than the 
earlier products. For use on a rather small scale especially, or where 
expense is not a limiting factor, satisfactory commercial dusts are now 
available. The great drawback lies in the fact that in numerous cases 
where nicotine dusting has peculiar advantages in the control of seri- 
ous inse( 1 p Is, the use of this method is prevented, or seriously 
handicapped, by the high cost of the material. 



Bulletin 357] 



SELF-MIXING DUSTING MACHINE 



499 




Pig. 1. — Demonstration of self-mixing duster at Walnut Growers ' Field Day, 
Goleta, California, September 2, 1922. 



500 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 

Bulletin 336, under the discussion of "How May Nicotine Dust 
Be Improved and Cheapened," contains the following paragraph: 

" SUGGESTION OF A NEW TYPE OF DUSTING MACHINE" 

! ' In conjunction with Mr. W. W. Thomas the writer has developed 
somewhat the idea of a combined dusting and mixing machine, the 
plan being to place the raw materials in the machine in the field 
and do the mixing in the hopper of the dusting machine, just as is 
done in the tank of a liquid sprayer. Such a machine, if feasible, 
would have the following advantages : The grower could buy materials 
like 'Black Leaf 40,'* hydrated lime and sulphur almost as cheaply 
as the present dust manufacturers and save the expense of mixing, 
containers, 'overhead,' several profits, and much of the freight. He 
could vary the strength of the mixture according to his needs. Little 
or no nicotine would be lost in the process of mixing and handling. The 
first full strength of the nicotine and ammonia when set free from 
'Black Leaf 40,'* by lime would be utilized. By adding a small amount 
of quick-lime, or other material, heat could be developed in the mixture 
and the dust discharged in such a hot condition that the nicotine 
would be very volatile and active, and a smaller amount of 'Black 
Leaf 40'* would therefore be required. This is perhaps the greatest 
advantage of all in the use of this method. 

' ' The idea of the machine which we have had in mind contemplates 
a hopper containing a mixing screw, into Avhich finely pulverized 
and liquid materials would be placed in the proper proportions. Hy- 
drated lime would be the most generally available filler material, with 
'Black Leaf 40'* as a source of nicotine. Pulverized quick lime or 
'Dry Lime Sulphur' could be added if necessary for drying, or for 
producing heat. From the hopper, after brief mixing, the material 
would be drawn through the fan (using an exhauster) rather than 
blowing it out ahead of the fan as in the present machines. The action 
of the fan would complete the mixing and break up the nicotine lumps. 
This would, of course, be a power machine ; for hand use, ready-made 
mixtures would still be required. 



■> ■> 



CONSTRUCTION OF THE SELF-MIXING DUSTER 

In the furtherance of this idea a machine which thus far has 

been entirely satisfactory was developed in 1922. The point was, 

?is suggested in the quotation above, to place in the hopper a fairly 

high speed agitator for a preliminary mixing, then to break up 

the lumps by passing the material through the fan. The latter 

principle was found already embodied in the power duster put 

* When this was written "Black Loaf 40" was practically the only nicotine 
sulfate «>n the market. Several other brands of equal nicotine content are now 
available. 



Bulletin 357] 



SELF-MIXING DUSTING MACHINE 



501 




Fig. 2. — Vertical section drawing of self -mixing cluster. A, drive shaft, 
gears and top. B, iron collar added to increase capacity of hopper. C, agitator 
shaft and blades. D, scraper. 



502 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 

on the market in 1922 by the Dosch Chemical Company of Louisville, 
Kentucky. The machine illustrated in figures 1, 2, and 3 was built 
by remodeling one of these dusters, lent for the purpose by Mr. F. A. 
Frazier of San Francisco, western representative of the Dosch Com- 
pany. The changes made in the original machine were as follows: 
The height and capacity of the hopper were increased by means of 
the ten-inch black iron ring or collar forming the upper part of the 
hopper as shown in the illustrations (fig. 2 B). The original lid, 
drive-shaft, and gears were discarded. A wooden lid was fitted to the 
top and a drive-shaft with pulleys mounted as it is shown (fig. 2 A), 
A vertical shaft in the center of the hopper was driven by means of 
gears from the cross shaft. To this center shaft were attached hori- 
zontal arms made of two by one-fourth inch iron, sharpened on the 
front edge and slightly turned up on the ends, extending almost to 
the sides of the hopper, (fig. 2 C). There are three sets of blades, 
comprising four each. Vertical blades or scrapers were attached to 
the ends of two of the arms in the middle and lower set (fig. 2D). 
This formed the agitator. The feeding device in the bottom of the 
hopper was not changed. The various pulleys and gears are of such 
sizes as to give a speed of 120 revolutions per minute in the agitator, 
and 3000 revolutions per minute in the fan. Nothing about the arrange- 
ment, shape, or style of this particular machine is to be looked upon 
as a finished product or as a model for permanent use. The funda- 
mental idea is to have a machine with a fairly rapid, efficient agitator 
in the hopper, and one in which the dust passes through the fan. 
No patent rights are involved in securing these essentials. As to the 
rest of the machine, it is not at all necessary to use any exclusive 
features of the Dosch or any other duster. The contrivance we have 
pictured is simply a crude device, built in the easiest possible manner 
compatible with carrying out the idea involved. A machine could 
easily be designed to work either with factory-mixed dust or as a 
self-mixer. 

HOW THE SELF-MIXER WORKS 

In making nicotine dust with such a machine, a sack (100 pounds) 
of hydrated lime is first dumped into the hopper. The desired amount 
of nicotine solution (usually from one to five pounds) is then poured 
in onto the lime, the lid is closed and the machine started. When the 
machine was first used, it was thought that it would be necessary to 
run the agitator five or ten minutes before starting to dust, but this 
proved to be unnecessary. With the agitator running at 120 revolu- 
tions per minute, only a few seconds are required to mix the mass 



Bulletin 357] 



SELF-MIXING DUSTING MACHINE 



503 




Fig. 3. — Dusting walnut trees with self-mixing duster. 



504 UNIVERSITY OF CALIFORNIA — EXPERIMENT STATION 

thoroughly enough so that it feeds down into the fan in the right pro- 
portion. Hydrated lime is mentioned because it is cheap, finely pulver- 
ized, and easily available. 

POWER REQUIRED 

The machine was run with a four horse-power Cushman engine, 
which gave ample power. 

MAKING DRY MIXTURES 
In tree dusting it is often desirable to mix sulfur, lead arsenate, 
dehydrated copper sulfate, and other powders with lime or with 
each other. Such mixing is quickly, thoroughly, and cheaply accom- 
plished with this type of machine, and may be done in any desired 
proportion. Nicotine solution may also be added to these materials. 

ADDITION OF MATERIALS TO HEAT THE DUST 
All experience has shown that the action of nicotine dust is one 
of fumigation and that it is therefore desirable to make the nicotine 
just as volatile as possible. This is largely effected by temperature. 
By mixing with the nicotine dust five to ten per cent of pulverized 
quick lime, dry lime sulfur (calcium polysulfide), soluble sulfur 
(sodium polysulfide), or other caustic materials, heat may be pro- 
duced and the effectiveness of the nicotine thus increased. The sul- 
fides have also some insecticidal effect in themselves. The further 
addition of a little kerosene adds to the effect. The pulverized quick 
lime for this purpose must be specially prepared but the other ma- 
terials mentioned are available in many places. 

SAVNG IN COST AND OTHER ADVANTAGES OF THE SELF-MIXER 

The financial saving effected by such a machine is self-evident. 
With nicotine sulfate solution at $1.20 a pound and hydrated lime 
at 1 cent a pound, a 1% per cent dust, such as that used for walnut 
aphis would cost 3 cents a pound, while a 5 per cent dust would cost 
7 cents. This is less than half the usual f .o.b. price of similar factory- 
made mixtures. The saving in cost would be less important if the 
ready-mixed dust were in any way superior to the machine-mixed 
variety, but exactly the opposite is true. 

The advantages of the self -mixer may be again enumerated as: 
1. No expense, save that of the raw materials. 2. No loss of nicotine. 
3. No carrying over of mixtures and consequent deterioration after 
the season has ended. 4. Possibility of applying dust hot. 5. Possi- 
bility of making mixtures in any desired proportions. 



Bulletin 357] 



SELF-MIXING DUSTING MACHINE 



505 




Fig. 4. — Two self-mixing dusters which are now on the market. Above, 
machine made by Smith Manufacturing Co., San Jose, Cal. Below, Bean Spray 
Pump Co., San Jose, California. 



506 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION 



LIMITATIONS OF THE SELF-MIXER 

It should not be thought that the use of this machine will entirely 
take the place of the use of factory-mixed dust. The idea, at present, 
applies only to a large power machine and is impracticable where hand 
machines are employed, or in any small scale work. Furthermore, 
many growers prefer ready-made material to anything which requires 
accurate measurement and mixing of materials in the field. The self- 
mixing machine, by increasing the practice of dusting, promises to 
supplement and extend the use of ready-made mixtures rather than to 
supplant or lessen their use. 

SELF-MIXING DUSTERS IN 1923 

This division has cooperated with the Smith Manufacturing Com- 
pany and the Bean Spray Pump Company, both of San Jose, Cali- 
fornia, in the development of the self -mixing dusters shown in figure 
4. Mr. A. P. Craig of Morgan Hill, California, originally devised 
both of these machines for ordinary dusters, while Mr. W. W. Thomas 
formerly of this division, did much of the work of converting them 
into self -mixers. 

FREE NICOTINE USED INSTEAD OF NICOTINE SULFATE 

Experience is showing that a dust made with free nicotine is more 
powerful, unit for unit, than one in which nicotine sulfate is used. 
The free nicotine solution also mixes and spreads through the carrier 
better than the sulfate, as it contains less solids and gummy material. 
A very good nicotine dust for home garden use can be made by simply 
stirring up together five pounds of sulfur and % pound of 40 per 
cent free nicotine solution, several brands of which are in the market. 
This mixture is improved by standing for a day or two in an air- 
tight can. 



STATION PUBLICATIONS AVAILABLE FOE FKEE DISTEIBUTION 



BULLETINS 

No. No. 

253. Irrigation and Soil Conditions in the 328. 

Sierra Nevada Foothills, California. 331. 

261. Melaxuma of the Walnut, "Juglans 332. 

regia." 334. 

262. Citrus Diseases of Florida and Cuba 

Compared with these of California. 335. 

263. Size Grades for Ripe Olives. 

268. Growing and Grafting Olive Seedlings. 336. 

270. A Comparison of Annual Cropping, Bi- 
ennial Cropping, and Green Manures 337. 
on the Yield of Wheat. 339. 

273. Preliminary Report on Kearney Vine- 
yard Experimental Drain. 340. 

275. The Cultivation of Belladonna in Cali- 

fornia. 341. 

276. The Pomegranate. 342. 

278. Grain Sorghums. 343. 

279. Irrigation of Rice in California. 344. 

280. Irrigation of Alfalfa in the Sacramento 

Valley. 345. 

283. The Olive Insects of California. 

285. The Milk Goat in California. 346. 

286. Commercial Fertilizers. 347. 

287. Vinegar from Waste Fruits. 

294. Bean Culture in California. 348. 

297. The Almond in California. 349. 

298. Seedless Raisin Grapes. 

299. The Use of Lumber on California Farms. 350. 
304. A study on the Effects of Freezes on 351. 

Citrus in California. 352. 
308. I. Fumigation with Liquid Hydrocyanic 

Acid. II. Physical and Chemical Prop- 353. 

erties of Liquid Hydrocyanic Acid. 354. 

312. Mariout Barley. 355. 

313. Pruning Young Deciduous Fruit Trees. 356. 

316. The Kaki or Oriental Persimmon. 

317. Selections of Stocks in Citrus Propa- 357. 

gation. 
319. Caprifigs and Caprification. 
321. Commercial Production of Grape Syrup. 358. 

324. Storage of Perishable Fruit at Freezing 

Temperatures. 359. 

325. Rice Irrigation Measurements and Ex- 

periments in Sacramento Valley, 
1914-1919. 



Prune Growing in California. 

Phylloxera-Resistant Stocks. 

Walnut Culture in California. 

Preliminary Volume Tables for Second- 
Growth Redwoods. 

Cocoanut Meal as a Feed for Dairy 
Cows and Other Livestock. 

The Preparation of Nicotine Dust as 
an Insecticide. 

Some Factors of Dehydrater Efficiency. 

The Relative Cost of Making Logs from 
Small and Large Timber. 

Control of the Pocket Gopher in Cali- 
fornia. 

Studies on Irrigation of Citrus Groves. 

Hog Feeding Experiments. 

Cheese Pests and Their Control. 

Cold Storage as an Aid to the Market- 
ing of Plums. 

Fertilizer Experiments with Citrus 
Trees. 

Almond Pollination. 

The Control of Red Spiders in Decidu- 
ous Orchards. 

Pruning Young Olive Trees. 

A Study of Sidedraft and Tractor 
Hitches. 

Agriculture in Cut-over Redwood Lands. 

California State Dairy Cow Competition. 

Further Experiments in Plum Pollina 
tion. 

Bovine Infectious Abortion. 

Results of Rice Experiments in 1922. 

The Peach Twig Borer. 

Observations on Some Rice Weeds in 
California. 

A Self-mixing Dusting Machine for 
Applying Dry Insecticides and 
Fungicides. 

Black Measles, Water Berries, and 
Related Vine Troubles. 

Fruit Beverage Investigations. 



CIRCULARS 

No. No. 

70. Observations on the Status of Corn 166. 

Growing in California. 167. 

82. The Common Ground Squirrel of Cali- 169. 

fornia. 170. 
87. Alfalfa. 

110. Green Manuring in California. 172. 

111. The Use of Lime and Gypsum on Cali- 173. 

fornia Soils. 

113. Correspondence Courses in Agriculture. 174. 

117. The Selection and Cost of a Small 175. 

Pumping Plant. 

127. House Fumigation. 178. 

136. Melilotus indica as a Green-Manure 179. 

Crop for California. 

144. Oidium or Powdery Mildew of the Vine. 182. 
148. "Lungworms." 

151. Feeding and Management of Hogs. 183. 

152. Some Observations on the Bulk Hand- 184. 

ling of Grain in California. 188. 

155. Bovine Tuberculosis. 190. 

157. Control of the Pear Scab. 193. 

159. Agriculture in the Imperial Valley. 198. 

160. Lettuce Growing in California. 199. 

161. Potatoes in California. 201. 
165. Fundamentals of Sugar Beet Culture 202. 

under California Conditions. 



The Country Farm Bureau. 
Feeding Stuffs of Minor Importance. 
The 1918 Grain Crop. 
Fertilizing California Soils for the 1918 

Crop. 
Wheat Culture. 
The Construction of the Wood-Hoop 

Silo. 
Farm Drainage Methods. 
Progress Report on the Marketing and 

Distribution of Milk. 
The Packing of Apples in California. 
Factors of Importance in Producing 

Milk of Low Bacterial Count. 
Extending the Area of Irrigated Wheat 

in California for 1918. 
Infectious Abortion in Cows. 
A Flock of Sheep on the Farm. 
Lambing Sheds. 

Agriculture Clubs in California. 
A Study of Farm Labor in California. 
Syrup from Sweet Sorghum. 
Onion Growing in California. 
Helpful Hints to Hog Raisers. 
County Organizations for Rural Fire 

Control. 



CIRCULARS — Continued 



No. No. 

203. Peat as a Manure Substitute. 237. 

205. Blackleg. 

206. Jack Cheese. 238. 

208. Summary of the Annual Reports of the 239. 

Farm Advisors of California. 

209. The Function of the Farm Bureau. 240. 

210. Suggestions to the Settler in California. 

212. Salvaging Rain-Damaged Prunes. 241. 

214. Seed Treatment for the Prevention of 

Cereal Smuts. 242. 

215. Feeding Dairy Cows in California. 244. 

217. Methods for Marketing Vegetables in 245. 

California. 246. 

218. Advanced Registry Testing of Dairy 

Cows. 247. 

219. The Present Status of Alkali. 248. 

224. Control of the Brown Apricot Scale 

and the Italian Pear Scale on Decid- 249. 

uous Fruit Trees. 250. 

225. Propagation of Vines. 

228. Vineyard Irrigation in Arid Climates. 251. 
230. Testing Milk, Cream, and Skim Milk 
for Butterfat. 

232. Harvesting and Handling California 252. 

Cherries for Eastern Shipment. 253. 

233. Artificial Incubation. 254. 

234. Winter Injury to Young Walnut Trees 

during 1921-22. 255. 

235. Soil Analysis and Soil and Plant Inter- 

relations. 256. 

236. The Common Hawks and Owls of Cali- 257. 

fornia from the Standpoint of the 258. 

Rancher. 259. 



Directions for the Tanning and Dress- 
ing of Furs. 

The Apricot in California. 

Harvesting and Handling Apricots and 
Plums for Eastern Shipment. 

Harvesting and Handling Pears for 
Eastern Shipment. 

Harvesting and Handling Peaches for 
Eastern Shipment. 

Poultry Feeding. 

Central Wire Bracing for Fruit Trees. 

Vine Pruning Systems. 

Desirable Qualities of California Bar- 
ley for Export. 

Colonization and Rural Development. 

Some Common Errors in Vine Pruning 
and Their Remedies. 

Replacing Missing Vines. 

Measurement of Irrigation Water on 
the Farm. 

Recommendations Concerning the Com- 
mon Diseases and Parasites of 
Poultry in California. 

Supports for Vines. 

Vineyard Plans. 

The Use of Artificial Light to Increase 
Winter Egg Production. 

Leguminous Plants as Organic Fertil- 
izer in California Agriculture. 

The Control of Wild Morning Glory. 

The Small-Seeded Horse Bean. 

Thinning Deciduous Fruits. 

Pear By-products. 



